<!DOCTYPE html>
<html lang="en">

<head>
    <title>Love</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
    <style>
        body {
            font-family: Monospace;
            background-color: #f0f0f0;
            margin: 0px;
            overflow: hidden;
        }
    </style>
</head>

<body>


    <script src="js/nb.js"></script>

    <script src="js/Projector.js"></script>
    <script src="js/CanvasRenderer.js"></script>

    <script src="js/tween.min.js"></script>
    <script src="js/Sparks.js"></script>

    <!-- load the font file from canvas-text -->

    <script src="js/helvetiker_regular.typeface.js"></script>


    <script>

        var container;

        var camera, scene, renderer;

        var group, text, plane;

        var targetRotation = 0;
        var targetRotationOnMouseDown = 0;

        var mouseX = 0;
        var mouseXOnMouseDown = 0;

        var windowHalfX = window.innerWidth / 2;
        var windowHalfY = window.innerHeight / 2;

        var heartShape, particleCloud, sparksEmitter, emitterPos;
        var _rotation = 0;
        var timeOnShapePath = 0;

        init();
        animate();

        function init() {

            container = document.createElement('div');
            document.body.appendChild(container);


            //相机
            camera = new THREE.PerspectiveCamera(50, window.innerWidth / window.innerHeight, 1, 1000);
            camera.position.set(0, 150, 800);

            //场景
            scene = new THREE.Scene();

            group = new THREE.Group();
            scene.add(group);

            // Get text from hash

            var string = "Love";
            var hash = document.location.hash.substr(1);

            if (hash.length !== 0) {

                string = hash;

            }

            var text3d = new THREE.TextGeometry(string, {
                size: 80,
                height: 20,
                curveSegments: 2,
                font: "helvetiker"

            });

            text3d.computeBoundingBox();
            var centerOffset = -0.35 * (text3d.boundingBox.max.x - text3d.boundingBox.min.x);

            var textMaterial = new THREE.MeshBasicMaterial({ color: Math.random() * 0xffffff, overdraw: 0.5 });

            text = new THREE.Mesh(text3d, textMaterial);

            // Potentially, we can extract the vertices or faces of the text to generate particles too.
            // Geo > Vertices > Position

            text.position.x = centerOffset;
            text.position.y = 100;
            text.position.z = 0;

            text.rotation.x = 0;
            text.rotation.y = Math.PI * 2;

            group.add(text);


            particleCloud = new THREE.Object3D(); // Just a group
            particleCloud.y = 800;
            group.add(particleCloud);

            // Create Particle Systems

            // Heart

            var x = 0, y = 0;

            heartShape = new THREE.Shape();

            heartShape.moveTo(x + 25, y + 25);
            heartShape.bezierCurveTo(x + 25, y + 25, x + 20, y, x, y);
            heartShape.bezierCurveTo(x - 30, y, x - 30, y + 35, x - 30, y + 35);
            heartShape.bezierCurveTo(x - 30, y + 55, x - 10, y + 77, x + 25, y + 95);
            heartShape.bezierCurveTo(x + 60, y + 77, x + 80, y + 55, x + 80, y + 35);
            heartShape.bezierCurveTo(x + 80, y + 35, x + 80, y, x + 50, y);
            heartShape.bezierCurveTo(x + 35, y, x + 25, y + 25, x + 25, y + 25);

            var hue = 0;

            var hearts = function (context) {

                context.globalAlpha = 0.5;
                var x = 0, y = 0;
                context.scale(0.05, -0.05); // Scale so canvas render can redraw within bounds
                context.beginPath();
                // From http://blog.burlock.org/html5/130-paths
                context.bezierCurveTo(x + 2.5, y + 2.5, x + 2.0, y, x, y);
                context.bezierCurveTo(x - 3.0, y, x - 3.0, y + 3.5, x - 3.0, y + 3.5);
                context.bezierCurveTo(x - 3.0, y + 5.5, x - 1.0, y + 7.7, x + 2.5, y + 9.5);
                context.bezierCurveTo(x + 6.0, y + 7.7, x + 8.0, y + 5.5, x + 8.0, y + 3.5);
                context.bezierCurveTo(x + 8.0, y + 3.5, x + 8.0, y, x + 5.0, y);
                context.bezierCurveTo(x + 3.5, y, x + 2.5, y + 2.5, x + 2.5, y + 2.5);
                context.fill();
                context.lineWidth = 0.5; //0.05
                context.stroke();

            }

            var setTargetParticle = function () {

                var material = new THREE.SpriteCanvasMaterial({
                    program: hearts
                });

                material.color.setHSL(hue, 1, 0.75);
                hue += 0.001;
                if (hue > 1)
                    hue -= 1;

                particle = new THREE.Sprite(material);

                particle.scale.x = particle.scale.y = Math.random() * 40 + 40;
                particleCloud.add(particle);

                return particle;

            };

            var onParticleCreated = function (p) {

                p.target.position.copy(p.position);

            };

            var onParticleDead = function (particle) {

                particle.target.visible = false;
                particleCloud.remove(particle.target);

            };

            sparksEmitter = new SPARKS.Emitter(new SPARKS.SteadyCounter(160));

            emitterpos = new THREE.Vector3();

            sparksEmitter.addInitializer(new SPARKS.Position(new SPARKS.PointZone(emitterpos)));
            sparksEmitter.addInitializer(new SPARKS.Lifetime(0, 2));
            sparksEmitter.addInitializer(new SPARKS.Target(null, setTargetParticle));

            sparksEmitter.addInitializer(new SPARKS.Velocity(new SPARKS.PointZone(new THREE.Vector3(0, -50, 10))));

            // TOTRY Set velocity to move away from centroid

            sparksEmitter.addAction(new SPARKS.Age());
            //sparksEmitter.addAction(new SPARKS.Accelerate(0.2));
            sparksEmitter.addAction(new SPARKS.Move());
            sparksEmitter.addAction(new SPARKS.RandomDrift(50, 50, 2000));

            sparksEmitter.addCallback("created", onParticleCreated);
            sparksEmitter.addCallback("dead", onParticleDead);
            sparksEmitter.addCallback("updated", function (particle) {

                particle.target.position.copy(particle.position);

            });

            sparksEmitter.start();

            // End Particles


            renderer = new THREE.CanvasRenderer();
            renderer.setClearColor(0xf0f0f0);
            renderer.setPixelRatio(window.devicePixelRatio);
            renderer.setSize(window.innerWidth, window.innerHeight);
            container.appendChild(renderer.domElement);

            document.addEventListener('mousedown', onDocumentMouseDown, false);
            document.addEventListener('touchstart', onDocumentTouchStart, false);
            document.addEventListener('touchmove', onDocumentTouchMove, false);

            //

            window.addEventListener('resize', onWindowResize, false);

        }

        function onWindowResize() {

            windowHalfX = window.innerWidth / 2;
            windowHalfY = window.innerHeight / 2;

            camera.aspect = window.innerWidth / window.innerHeight;
            camera.updateProjectionMatrix();

            renderer.setSize(window.innerWidth, window.innerHeight);

        }

        //

        document.addEventListener('mousemove', onDocumentMouseMove, false);

        function onDocumentMouseDown(event) {

            event.preventDefault();

            mouseXOnMouseDown = event.clientX - windowHalfX;
            targetRotationOnMouseDown = targetRotation;

            if (sparksEmitter.isRunning()) {

                sparksEmitter.stop();

            } else {

                sparksEmitter.start();

            }

        }

        function onDocumentMouseMove(event) {

            mouseX = event.clientX - windowHalfX;

            targetRotation = targetRotationOnMouseDown + (mouseX - mouseXOnMouseDown) * 0.02;

        }

        function onDocumentTouchStart(event) {

            if (event.touches.length == 1) {

                event.preventDefault();

                mouseXOnMouseDown = event.touches[0].pageX - windowHalfX;
                targetRotationOnMouseDown = targetRotation;

            }

        }

        function onDocumentTouchMove(event) {

            if (event.touches.length == 1) {

                event.preventDefault();

                mouseX = event.touches[0].pageX - windowHalfX;
                targetRotation = targetRotationOnMouseDown + (mouseX - mouseXOnMouseDown) * 0.05;

            }

        }

        //

        function animate() {//更新场景

            requestAnimationFrame(animate);

            render();

        }

        function render() {

            timeOnShapePath += 0.0337;

            if (timeOnShapePath > 1)
                timeOnShapePath -= 1;

            // TODO Create a PointOnShape Action/Zone in the particle engine
            var pointOnShape = heartShape.getPointAt(timeOnShapePath);

            emitterpos.x = pointOnShape.x * 5 - 100;
            emitterpos.y = -pointOnShape.y * 5 + 400;

            // Pretty cool effect if you enable this
            // particleCloud.rotation.y += 0.05;

            group.rotation.y += (targetRotation - group.rotation.y) * 0.05;
            renderer.render(scene, camera);
        }

    </script>

</body>

</html>